Polylactic acid resins have some features that polylactic acid resins are inexpensive because L-lactic acid used as a raw material is produced from sugars extracted from maize, potato or the like according to a fermentation method, that an amount of carbon dioxide discharged is very small because the raw materials are derived from plants, and that the resins have such properties as being strongly rigid and highly transparent, so that the utilization of the polylactic acid resins is expected at present.
Patent Publication 1 discloses as a polylactic acid-based resin composition having excellent crystallinity capable of molding a foamed article having excellent flame-retardant property and heat resistance, a polylactic acid-based resin composition containing a polylactic acid resin (A), a (meth)acrylic ester compound (B), and a specified flame retardant (C). In addition, the patent publication describes that the composition is blended with a crystal nucleating agent for accelerating crystallization, or blended with a foaming nucleating agent or an epoxy group-containing chain extender for the purpose of controlling sizes of foams and foaming folds when a foamed article is obtained.
Patent Publication 2 discloses as an aliphatic polyester resin composition having excellent impact resistance, a resin composition containing (A) an aliphatic polyester, (B) a multi-layered structured polymer, and (C) a reactive compound containing one or more functional groups selected from a glycidyl group, an acid anhydride group, a carbodiimide group, and an oxazoline group. Also, the patent publication discloses that the composition contains a crystal nucleating agent and a plasticizer, from the viewpoint of improving heat resistance.
In addition, Patent Publication 3 discloses as a resin composition having excellent impact resistance, a resin composition containing a polylactic acid resin, a polypropylene-based resin, a compatibilizing agent, and a crystal nucleating agent, wherein the above crystal nucleating agent is at least one member selected from the group consisting of compounds having a hydroxyl group and an amide group in the molecule, metal salts of phenylphosphonic acids, phthalocyanine, metal salts of phosphoric esters, metal salts of dialkyl esters of aromatic sulfonic acids, metal salts of rosin acids, aromatic carboxylic acid amides, rosin acid amides, carbohydrazides, N-substituted ureas, salts of melamine compounds, and uracils.
Patent Publication 1: Japanese Patent Laid-Open No. 2011-202079
Patent Publication 2: Japanese Patent Laid-Open No. 2007-119730
Patent Publication 3: Japanese Patent Laid-Open No. 2010-100759